Technical Abstract:
Past emphasis on repeatability of analytical measurements within a specific set of generated data has expanded to include interest and demand for a present focus on the accuracy of analytical data so that valid comparisons can be made among individual sets of data. Well characterized materials of known content (Reference Materials) play a critical role in transferring accuracy throughout a measurement hierarchy. Primary or certified standard are generally internationally recognized with an undisputed level of analytical confidence and are designed for initial or periodical testing of the performance of a new analytical technique. Secondary Reference materials are a "work horse" version of a primary standard, with content confirmed outside the specific point of use, and are meant for frequent use in assurance of correct method performance. Tertiary or In-house reference materials are characterized internal to specific application and are used in a frequent quality control mode. Food based reference materials are available from several sources both within the U.S. and internationally. Reference materials are used by all food testing and analysis laboratories to ensure accuracy and thus comparability of analytical data.